Both sickle cell anemia and beta-thalassemia are serious clincial disorders resulting from mutations affecting the adult beta-globin gene. Numerous epidemological studies have suggested that increased production of fetal hemoglobin in sufficient quantities can ameliorate the clinical serviety of both disorders. The purpose of this pilot study is to determine the range of responses to intravenous arginine butyrate as gauged by the increase in fetal hemoglobin production in patients with sickle cell anemia and beta-thalassemia syndromes.